I think this would be a great product, and yes, I see value in it. Maybe this could go deeper. Many engineer founders want a Christmas tree of features. This process could help them trim the fat and actually optimize for PMF.
You're absolutely right about the depth—the narrative constraint acts as a forcing function. When you have to explain your value in just 10 slides, you realize 80% of those features don't actually drive the core mission. It definitely ends up being a PMF exercise as much as a pitch exercise.
Appreciate the feedback!